Process for the preparation of strontium ranelate
Inventors
Divi, Murali Krishna Prasad • Rao, Mysore Aswatha Narayana • Nowshuddin, Shaik
Assignees
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Publication Number
US-8569514-B1
Publication Date
2013-10-29
Expiration Date
Abstract
Strontium ranelate is prepared by reacting dicyclohexylammonium ranelate with strontium halide in an anhydrous solvent. Strontium ranelate thus obtained will have less than 3% moisture content.
Core Innovation
The invention relates to a process for the preparation of strontium ranelate having less than 3% moisture content. The process comprises reacting ranelic acid with dicyclohexylamine in an anhydrous solvent to obtain dicyclohexylammonium ranelate salt, followed by reacting the dicyclohexylammonium ranelate salt with strontium halide in an anhydrous solvent to obtain strontium ranelate.
A key element is the formation of a water-insoluble dicyclohexylammonium ranelate salt from ranelic acid and dicyclohexylamine in an organic solvent. The dicyclohexylammonium ranelate salt is then used in a salt exchange with anhydrous strontium halide in an anhydrous solvent to precipitate strontium ranelate.
The described approach is presented as milder than prior azeotropic/thermal drying approaches that are associated with impurity formation. The disclosed outcome is strontium ranelate with low moisture content, including moisture levels such as 1.7–2.2% in the examples, together with high yield/purity as highlighted in the document content.
Claims Coverage
The document includes two independent claims. One claim covers a two-step anhydrous salt-exchange process to obtain strontium ranelate with less than 3% moisture content, and the other claim covers a defined dicyclohexylammonium ranelate salt composition with a 2:1 ratio.
Anhydrous salt-exchange process to obtain strontium ranelate with less than 3% moisture
Reacting ranelic acid with dicyclohexylamine in an anhydrous solvent to obtain dicyclohexylammonium ranelate salt; and reacting the dicyclohexylammonium ranelate salt with strontium halide in an anhydrous solvent to obtain strontium ranelate.
Dicyclohexylammonium ranelate salt defined by 2:1 ratio
Dicyclohexylammonium ranelate salt having dicyclohexylamine and ranelic acid in a ratio of 2:1.
Overall, claim coverage centers on an anhydrous preparation route using dicyclohexylammonium ranelate salt formation and subsequent salt exchange with strontium halide to obtain strontium ranelate with low moisture, and on a specific defined dicyclohexylammonium ranelate salt composition in a 2:1 dicyclohexylamine-to-ranelic-acid ratio.
Stated Advantages
Preparation of strontium ranelate with less than 3% moisture content, including 1.7–2.2% moisture in examples.
Milder conditions that avoid impurity formation seen in prior azeotropic/thermal drying approaches.
High yield/purity is reported.
Documented Applications
No documented applications found
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